When performing spinal surgery such as when inserting interbody fusion devices between adjacent vertebrae, the endplates of the adjacent vertebrae are first preferably decorticated to encourage the growth of bone and cause bone fusion by exposing cancellous bone. Additionally, osteophytes projecting outwardly from the sides of the vertebrae should be removed during surgery as they may damage nerves or other soft tissues.
Typically, curettes, scrapers or other filing instruments are used for osteophyte resection and chisels or drills are used for removing bone cortical tissue. It is not possible to leverage conventional curettes or scrapers against the vertebrae while operating these devices since these devices must move freely back and forth against the osteophyte to wear it down. Conventional decortication systems are also limited. In particular, when decorticating with a chisel or drill, substantially all of the cortical tissue is typically removed during the procedure. It would instead be preferable to provide decortication in the form of deep scratches on the vertebral endplates, thereby not removing all cortical tissue. An advantage of not removing all cortical tissue is that the vertebrae will retain sufficient structural support to hold an intervertebral insert firmly in position.
During minimally invasive spinal surgery, access to a patient's intervertebral space can be provided through a cannulated percutaneous posterolateral approach. An example of such minimally invasive surgery is described in the Applicant's provisionally filed patent application entitled "Minimally Invasive Spinal Surgery Systems", filed Jun. 9th, 1998, (Attorney Docket No. 18608-000600), incorporated herein by reference in its entirety.
Unfortunately, a disadvantage of present endplate decorticators and osteophyte resectors is the difficulty of firmly holding these devices against the vertebral surface being resected or decorticated during operation. As such devices can not be firmly leveraged against vertebral bones, the abrasion effectiveness of existing devices is somewhat limited. This disadvantage of existing endplate decorticators and osteophyte resectors is especially pronounced in the area of minimally invasive surgery. In particular, due to their large and bulky size, existing endplate decorticators and osteophyte resectors are not adapted to be received through percutaneously inserted cannulae into the patient's intervertebral space. Rather, existing decorticators and resectors are typically dimensioned such that they can only be used during highly invasive surgical procedures, such as when access to the patient's intervertebral space is accomplished by open spinal surgery.
An additional disadvantage of existing endplate decorticators and osteophyte resectors is that these exist as two very different devices. It would instead be desirable to provide a single device offering the combined benefits of endplate decorticators and osteophyte resectors.